Compensating device



Oct. 6, 1931.- J, M, DAYTQN 1,826,604

GOMPENSATING DEVICE Original Filed Jan. 21, 1929 ci. l

Patented ct. 6, 1931 JAMES M. DAYTON, 0F TCRRINGTON, CONNECTICUT COMPENSATING DEVICE Application filed January 21, 1929, Serial No. 834,035. Renewed August 28, 1931.

This invention relates fto improvements in compensating devices, more art-icuilarly intended for Ithe transmission ci) a movementfof any selected ,one of a number of members `to a counting mechanism whereby "the amounts of the movements yof the member are totalized by the counter, and in which the -member may makean individually predetermined distance of movement to accomplish a standard result.

One of Athe purposes of the present inven tion is to provide la structure of this nature in which very few elements are necessary of employment, .and `these elevents may be simply and cheaply constructed and adjusted y the connections of the several parts.

Fig. 2 isa view on a smaller scale, partly in perspective, showing the connection of a compensating device formeasur-ing and totalizing the .reciproca-tory movements of a pump piston.

Fig. 3 is a vertical section on line 3-3 of Fig. 1.

The invention `is illustrated :as applied to the compensation of 'a rectilinear movement f of predeterminedamount. Itis well known that in, for example, the reciprocating pumps used with gasoline dispensing apparatus, the cylinders of these pumps are constructed of tubing which will. vary in diameter owing .to

the/.processes of manufacture employed. Any

given pump cylinder will be of uniform diameter from end to end, but the cylinders of two pumps may diifer as muchas several percent. In order to calibrate the pump so that a full stroke will always give a definite quantity,-as for example a gallon,.afstop member provided which .may be'adjusted to regulate the pump stroke. It is, however, desired to totalize the plump movements so that a counting mechanism will :indicate 'at all times the actual quantity of liquid which has passed through the pump. It is therefore necessary to provide a compensator between the pump and the counting mechanism, whereby a full stroke of the pump will always cause a movement lof the counting device which corresponds to the volume of liquid delivered by the pump., i. e., in the example above the counting device must make a .movement to indicate one gallon, regardless of the actual length .of stroke of the piston itself.

Such a kcompensation is accomplished according to the present invention `by providing a means of fixed length upon the member whose movement is lto be measured, and so locating this means at an angle to the direction of movement, such that the movement of the member will cause a traversing .of the means `bodily by a given amount, but causing in this movement the relative vtranslation of a greater length of the said means. This length of the said means is then measured and totalized by the counting mechanism. By reason of thediference between the actual bodily translation of the said means, and the length oit the means which is so translated, it is possible to establishan exact calibration or compensationas may befdesired.

YOn the accompanying dra-wings, in '1, the principal working parts are shown on an enlarged scale, with the gear .train `illustnated respectively in two positions, bei-ng in the extended position in broken lines at the top and in a relatively collapsed position in full lines near the bottom. It will be understood that these .two positions represent relative movements of the rack and pinion.

rlhe pump cylinder 10 is shown as provided with .a piston l1 and having the inlet and outlet tap connections l2 and 13 which are provided in customary manner With rthe usual valves (not shown). The pump acts in the illustration as a single action pump, and its upward limit of travel is limited by the adjustable stop 14. .As pointed out above, when the pump is being calibrated, it is caused to move Yby such a distance 'that an exact gallon, forfexample, isxdelivered; and the -stop x14 is-adjusted to cause the maximum stroke vto beiof this distance. rPhe piston rod 15 of the pump has connected thereto an extension bar 15a which at its upper end has a rack 16 connected therewith by a pivot 17. The rack is provided with a number of teeth 18 of uniform pitch. A slotted link 19 is connected by a pivot 2O with the lower end of the link, and may be clamped by the bolt 21 at any part of its length to the extension 15a of the piston rod, whereby to determine the angle of the rack 16 with respect to the direction of movement of this extension 15a. This angle may be deiined as the angle included between the straight line joining the axes of the bolt 21 to the axis of the pivot 17, and the straight line joining the axes of the pivots 17 and 20, which will hereinafter he referred to as the angle of compensation.

lFixed to the frame of the pump is a strap 22. which has a slo 24 therein extending substantially at a right angle to the direction of movement of the piston rod 15. The slider block 25 is mounted for free movement in this slot, being constantly drawn toward the left by the coil spring 26. This block receives the pivot 27 for a. pinion 28 which meshes with the teeth 18 of the rack 1G. The pivot 27 likewise serves as a joint for connecting the block with a link 29 which carries a pivot and sha t 30 at its other end engaging with a similar link 31. The pivot and shaft 30 also serve as a bearing for the large idler gear 32 which is in mesh with the pinion 28. The second link 31 is likewise pivotally mountedabout a pivot shaft 33 carried by a block 34 likewise slidable in the slot 24, and also carrying a small intermediate idler' 35 meshing with the large idler 32. The end of the second link 31 carries a pivot and shaft 3G joining the second link 31 with a third link 37, and at the same time serving as a bearing for a second large idler 38 which is in mesh with the intermediate idler 35. The third link 37 at its other end is journaled on a pivot 39 fixed in the strap and serving as a shaft for the counting pinion 40, which is in mesh with the teeth of the second large idler 38.

The pinions 28 and 40 are of the same pitch diameter and have the same number of teeth: while the idlers 32 and 38 likewise are of the same respective diameters one with another, and have the same number of teeth. It will be noted that the pinions 28 and 40 and idlers 32 and 38 need not all have the same diameter and number of teeth, although they are alike in pairs. The number of teeth for the intermediate idler 35 may beA selected as desired.

In Fig. 3, a transverse section through the strap and parts is shown in which the rack 16 and the pinion 28 are represented as in plane and in engagement with one another, the rack pinion 28 being pivotally mounted on a sleeve 41 carried on the pin 42 which passes through the slot in the strap 22, and through the link 29, while a spacer' 43 is employed to enable the gear to turn freely.

The operation of the device is as follows:

then the piston 11 is down at the bottom of its stroke, the several parts are in the relative position indicated by the broken lines at the top of Fig. 1, the several pivots 27, 30, 33, 36 and 39 being almost in line. As the piston rod 15 moves upward, the rack teeth 18 engage with the teeth of pinion 28 and cause a clockwise rotation of the pinion 28, which is transmitted as a counterclockwise rotation of the idler 32, a clockwise rotation of the intermediate idler 35, a counterclockwise rotation of the idler 38, and finally a clockwise rotation of the counting gear 40, producing a drive of the shaft 39 (Fig. 2), transmitted through the uni-directional clutch 44 to the counting disks 45, which totalize the clockwise movement of the shaft 39, while a counterclockwise movement of this shaft is without eli'ect upon the counting mechanism 45 by reason of the slippage within the uni-directional clutch 44. lt will be noted that during this time, the axes 25, 33 and 39 have been maintained in a single plane by the engagement of the sliding members for the axes 25 and 33 in the slot 24 of the strap 22.

If the rack 16 does not lie in the direction of movement of the piston rod 15, i. e., if an angle of compensation is present as shown at ,B in Fig. 1, then the rack will tend to force the pinion 28 and therewith its axis 27 toward the right from the position shown in the broken lines in Fig. 1 to that shown in full lines. This movement of the pinion 28 toward the right results, however, owing to the links 29, 3l and 37, in a rocking of the pivot 30 and the idler 32 in a relatively clockwise direction about the axis 27 of the pinion 28, as indicated by the arrow 46 in Fig. 1; and hence by reason of the link 31 in a movement of the idler 38 in the direction indicated by the arrow 47. This collapsing of the three links 29, 31, 37 results in a shortening of the distance between the axes of pivots 27 and 39, and permits the pinion 28 to remain in contact with the rack 16 as the latter reciprocates.

It will be noted that the translation of the idler 32 about the axis 27 will result in the translation of a lesser angular movement from the pinion 28 to the idler 32: but any rotational movement of the idler 32 is exactly and immediately transmitted by the intermediate idler 35 to the second large idler 38, i. e., since the large idler 32 is turned relatively more slowly than it would were it not rocking with the link 39; therefore the large idler 38 is likewise moved more slowly, and hence it tends to move the counting pinion 4() through a greater angle than it would if such rocking did not occur. Since the pinions 28 and 4() are of the. same diameter and the idlers 32 and 38 are of the same diameter, and hence the lever arms between the axes 27 and 30, and axes 36 and 39 are of the same length, the angular translation of the large pinion 28 about the axis 27 is identical with the angular translation of the large idler 38 about the axis 39, and hence the rotation of the axis 27 is exactly reproduced in the rotation of the shaft 39.

A mathematical theory of the compensation may be given as follows: When the rack 16 is parallel to the direction of movement of the extension 15a, the pinion 28 revolves, and its axis 27 does not change position. `A twenty inch movement of the extension 15a and of the piston 11 will represent the passage of a twenty inch length of the rack past the axis 27. If the rack 16 has live teeth to the inch, this will mean that one hundred teeth of the rack have engaged and assisted in rotating the pinion 28, and that correspondingly the counting pinion 40 has rotated by one hundred teeth, and an indica- Ition corresponding to this one hundred-tooth movement has been set up on the counting mechanism 45, corresponding, for example, to the indication of a one gallon delivery.

If, however, the pump piston 11 need only make a nineteen inch movement to deliver one gallon, by reason of a greater diameter of the cylinder 10, then the extension 15a will only move nineteen inches in the relivery of the gallon. The rack 16 is then adjusted into a position shown in exaggerated form in Figs. 1 and 2 and held in this position by clamping the bolt 21. Owing to its angular presentation, the rack 16 now presents a greater number of teeth for rotating the pinion 28 during its nineteen inch movement than before, and with the exact calibration will present the same number of teeth, i. e., one hundred, during this nineteen inch movement as it formerly did during its twenty inch movement. In other words, the number of teeth presented by the rack is a trigonometric function of the angle and may be expressed as follows:

where ,8 is the angle of compensation, b the stroke of the pump when calibrated to deliver a unit quantity; and c is the length of the rack containing the proper number of teeth to cause an angular movement of the shaft 39 to indicate this unit `quantity in the counting mechanism 45. Further, the shaft 39 may itself be provided with a hand 50 ywhich will indicate the fractional quantity delivered by the given fractional strokes of the pump piston 11: it will be noted that this fractional hand 50 is reset to zero during the return movement of the pump piston rod 15.

The above description has been given for the full stroke upward of the rack 16. It is obvious that the same compensation appertains for any fractional stroke of the rack p 16. During the downward stroke of the rack rack in both directions may be totalized for a double acting pump, without change of the essential featuresl of the present invention.

It is preferred to provide the pinion 28 with a plate 28a flat against it and engaging with the plate 16a of the rack along the pitch circle and pitch line respectively of the pinion 28 and the rack 16, so that these parts move at all times in response to the movement of the pitch line of the rack.

Other changes may be made in the construction without departing from the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a device of the class described, an element actuated by and in proportion to the movement of a selected one of a number of devices having different lengths of stroke for' accomplishing a calibrated standard result, a rack secured to and moved with said element and extending at an angle to the direction of movement of such element, a pin ion in mesh with said rack, means to guide said pinion for movement at a right angle to the direction of movement of said element, a counter to indicate the movement of said element, means to hold said rack rigid with respect to said element so that such angle shall have its cosine equal to a fraction in which the numerator is the actual stroke of said first member and the denominator is the length of said rack required to operate said counter to an indication corresponding to said unitary result, and a gear train for constantly connecting said pinion to said counter.

2. A device of the class described includ ing a movable element, a pinion, a counter having an actuating gear, said counter being relatively fixed and said pinion relatively movable toward and from said counter, a gear train for constantly connecting said pinion and gear While permitting said pinion to move toward and from said counter, and a rack rigidly secured to and moved with said element and mounted at an angle to the direction of movement of said element'and in mesh with said pinion whereby to rotate said pinion and to move the latter with respect to said counter, and means t'o maintain said pinion constantly in mesh with said rack.

3. In a device as in claim 2, in which the transmitting means includes gears moved on parallel axes at av right angle to the direction of suoli movement and slidable at a right angle to the direction of said movement and ot said axes.

4. A device as in claim 2, in which the transmission means includes a pair of idler gears oic like number of teeth and an intermediate idler coupling said gears, two pinions of .like number ot teeth, one of said pinions meshing With one of said idler gears and rotated in inverse proportion to the cosine ot' said angle, and the other said pinion being coupled to said other member.

5. In a device as in claim Q, in which the transmission means includes a pair of idler gears of like number of teeth and an intermediate idler coupling sait. gears, two pinions of like number of teeth, one Vof said pinions meshing With one of said idler gears and rotated in inverse proportion to the cosine oit' said angle, the other said pinion being coupled to said other member, and further including two links pivotally connecting the pinion and meshing idler axis, and a link connecting the idler axes.

6. A device as in claim 2 in which the transmission means includes a pair ot idler gears of like number of teeth and an intermediate idler coupling said gears, two pinions of like number of teeth, one of said pinions meshing With one of said idler gears and rotated in inverse proportion to the cosine of said angle, the other said pinion beingl coupled to said other member, and means to guide the axes ot' said iirst pinion .and said intermediate idler for movement in a plane intersecting said second pinion axis.

7. In a. device of the class described, a moving element actuated by and in proportion to the movement ot any one of a number ot' .ly lined and the other relatively moved by said element, said actuating member including a transmitting member located at an angle to the direction of such relative movement, and transmitting means connected to said counter member to move the latter by a distance inversely proportional to the cosine ot' said angle, and means to hold said transmitting member at the angle Whose cosine is equal to the traction in which the numerator is the actual stroke of the said iirst member and the denominator is the length of said portion required to operate said counter to indication corresponding to said unitary result.

8. In a device of the class described, a rectilinearly movable member, a rectilinear rack mounted on said member at an angle to the direction of movement thereof, a pinion, means to hold said pinion constantly in mesh with said rack, tivo idler gears having like number of teeth and an intermediate idler constantly coupling said idler gears, one said idler gear meshing constantly with said pinion, a second pinion of the same number of teeth as said lirst pinion and meshing with said other idler gear, a counting member actuated by said second pinion, and means to guide the axes of said iirst pinion and said intermediate idler for movement in a plane passing through said second pinion axis.

9. In a device as in claim 8 for use with any one of a number of dispensing pumps whose pistons are adjusted to deliver the same calibrated standard volume, but with a length of stroke diitering according to the diameter of the cylinder, including means to establish and fix said angle so that its cosine is equal to 'the fraction in which the numerator is the actual stroke ot the said first member and the denominator is the length of said portion required to operate said counter to an indication corresponding to said unitary result.

l0. In a device of the class described, a moving element, a counter member, a linear rack, a gear train comprising gear Wheels in constant engagement one With another, one of said gear Wheels being constantly in mesh with said rack and another of said gear Wheels being connected to said counter member to actuate the same, means to adjust and secure said rack to said movement element at a predetermined angle with respect to the direction of movement thereof, and means to maintain said gear Wheels in such constant meshing engagement during the movement of the moving element.

1l. In a device of the class described, a moving element, a linear rack supported on said moving element to travel therewith, and means to adjust and secure said rack at a predetermined angle to the direction of movement of said moving element, a pinion meshing with said rack, ay counter, a second pinion to drive said counter, said first pinion being moved toward and from said second pinion during the movement of said moving element and rotated during such movement by its meshing engagement With said rack, and means to connect said pinions whereby their angular movements are proportional one to another.

In testimony whereof. I affix my signature.

JAMES M. DAYTON. 

